<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /*二  默认的主轴是y轴 column */
        div {
            display: flex;
            width: 800px;
            height: 800px;
            background-color: pink;
            /* 设置主轴是y轴 */
            flex-direction: column;
            /* 1.居中对齐 */
            justify-content: center;
              /* 2.两边贴边，在分配剩余空间 */
            justify-content: space-between;
           }
           span {
            width: 150px;
            height: 100px;
            background-color: skyblue;
           }
    </style>
</head>
<body>
    <div>
        <span>1</span>
        <span>1</span>
        <span>1</span>
        <span>1</span>
    </div>
</body>
</html>